1. Technical Field of the Invention
The present invention is related to an improved telecommunications network. In particular, the present invention relates to wireless telecommunications networks. More particularly, the present invention relates to cellular telephone networks. Still more particularly, the present invention relates to techniques for periodically notifying a telecommunications network of the availability of mobile stations within the telecommunications network.
2. Description of the Related Art
Present-day mobile telephony has spurred rapid technological advances in both wireless and non-wireless areas. The telecommunications industry is a rapidly growing industry, with advances, improvements, and technological breakthroughs occurring on an almost daily basis. Many mobile telecommunications systems, among them the European GSM-system, have already passed through several basic development phases and system designers are now concentrating on further improvements to the systems, including system refinements and the introduction of optional services.
Most wireless telecommunication systems currently in use are implemented as cellular telephone networks. Cellular telephone networks typically are composed of a group of base stations connected to a centrally located switch. This centrally located switch is commonly referred to as a Mobile Switching Center (MSC) . Base stations are usually spaced apart from each other by distances of between one-half and twenty kilometers. Each base station is assigned a number of two-way voice and control channels. The voice channels transmit voice signals to and from proximately located mobile stations, and transmit control information to and from these mobile stations, usually for the purpose of establishing a voice communications link.
A typical cellular telephone network also includes a group of interconnected mobile switching centers, which operate in association with a gateway mobile switching center through which the cellular telephone network interconnects with a conventional public switched telephone network (PSTN). In addition, at least one home location register (HLR) operates within the cellular telephone network. The HLR stores network subscriber information, including the identified location of current mobile stations within the network.
In response to an incoming call dialed to a mobile station, a signal is sent to the home location register requesting routing information through the network to the called mobile station. The home location register "looks up" the current location of the mobile station and contacts the currently serving mobile switching center to pre-route the call and retrieve a temporary location directory number, which is utilized to route the call through the cellular telephone network for delivery to the mobile station. The serving mobile switching center retrieves from a visitor location register (VLR), the identification of the cell within which the called mobile station is currently located. The mobile switching center then instructs the base station associated with that particular cell to page the mobile station. Responding to the page, the mobile station requests assignment of a channel, and the network routes the call through the serving mobile switching center and over the assigned channel.
Periodic updating, a well-known telecommunications technique, is a technique utilized in GSM-type telecommunications networks to periodically notify the network of the availability of mobile stations within the telecommunications network. Periodic updating may be accomplished utilizing location updating or routing area update procedures. Timers located at Mobile Stations within the network control the timing of such procedures. In a GSM-type telecommunications network, such timers may be located at an MSC. In a General Packet Radio Services (GPRS) telecommunications system, the timer may be located at a Serving GPRS Support Node (SGSN). A GPRS telecommunications system is a standardized switched data service for GSM based systems and networks.
Regardless of the type of telecommunications network utilized, such timers must currently be set manually. Correct timer settings are very important from a network-load point of view. A wrong setting may result in a serious overload in the network, particularly following a long network shutdown. The timers present at the mobile stations may additionally expire at an inopportune moment, causing a network overload and massive access requests for location updates. A setting that is too short may result in excessive signaling due to the generation of unnecessary location updates. A longer setting may result in inaccurate location identification for the mobile stations, which in turn promotes excess paging. An excess number of pagings may also contribute to an increase in the network load. Such excess pagings are usually unsuccessful. The timer settings themselves will vary according to the type of network utilized, the type of cells planned, coverage area, and so forth.
From the foregoing, it can be appreciated that a need exists for a reliable method and system for the automatic evaluation and implementation of timer settings in telecommunication networks. Such a method and system, if implemented, would serve to promote accurate and efficient periodic Location Update and Periodic Routing Area timers in GSM and GPRS systems, which would in turn create less havoc and frustration in telecommunication networks, as is the case with current timer configurations.